1. Technical Field of the Invention
The invention relates to a ceiling structure and more particularly to a sub-ceiling with a supporting framework in the form of a grid of intersecting bearing rails which support suspended panels is in a sealed manner.
2. Description of Related Art
Such a sub-ceiling is known, for example, from DE 28 58 140 C2. Longitudinal or horizontal bearing rails with T-shaped cross-sections of aluminium are used as bearing rails in the ceiling disclosed in this application. The longitudinal and horizontal rails are connected to each other by means of a connecting element. The disadvantage in this method of construction is the expensive manufacture of the special profiles and the lack of adaptability to various constructional axis dimensions. In addition the assembly of the relatively long longitudinal bearing rails is problematic. The connecting joints between the longitudinal and horizontal bearing rails can easily develop leaks, which should be avoided in clean-rooms used for industrial manufacture of electric or electronic components.